To solve a parking and stopping problem, a traffic problem, a traffic accident, and the like, the case in which camera imaging apparatuses such as black box and CCTV are equipped in a vehicle, a building, and the like has been increased.
In the case of the camera imaging apparatus, an image quality may rely on an exposure, and therefore a technology of automatically controlling an exposure of a camera to improve the image quality by an exposure control has been developed.
However, the existing method of automatically controlling an exposure of a camera controls an average gray of the overall image or an average gray value of some selected points to track a specific value.
The method makes the exposure different depending on surrounding environment and changes brightness of an illumination reflection point by a cornea and thus changes brightness of glint for each frame, which has an adverse effect on threshold setting for glint detection so as to make it difficult to track the glint.
Further, the glint is generally saturated over 255, and therefore when the saturation is absolutely suppressed, a face is too dark and thus face recognition may fail.